Celestron C11-SGT or CPC 1100 GPS

[Grahame (Grahame)]

Hello, I am looking at buying a new scope to replace the 6" that I currently own. I have narrowed the choices down to one of these 2, but was wondering which one would be better for astrophotography with a canon eos 20D. are there any major advantages in getting an EQ mounted scope conpared to the fork mounted one? With the CPC 1100 GPS scope being gps location enabled it would make the setting up much better when in different field locations but being a fork mount I might be restricted with a 20D hanging off it. Does anyone have any experance with these kind of mounts that might help in the decision of which scope is best??

[[1ponders] (Paul)]

Fork mounts are great for visual but to use them for photography you will need some sort of wedge to turn it into a pseudo equatorial mount. Without that all your image will rotate very quickly. If you intend to do imaging then an equatorial mount will be your best choice.

Don't expect wonders with the CG-5 mount though as IMO it is extremely undersize to carry a C11 for visual work, let alone photographic. Consider getting the C11 as OTA only and mounting it on an EQ6 or a CGE

[g__day (Matthew)]

Totally agree with the above, the Forks look sexy and convenient, but the German Equatorials are the real deal for most folk.

You could get a fork with a field de-rotator for a CCD, but not sure that could work with a Canon EOS!

I'd expect a well set up GE mount to run rings around an equivalent priced fork mount.

And as said above I don't see how a CG-5 with a weight limit of 14 Kgs is going to carry anything bigger than a 9.25" scope. I wouldn't put the 10" Meade on it even. If you really want a 11" scope I'd say you're looking at an EQ6 + skyscan for Goto as your best bet (mount like this costs around $2,300 at Andrews Communications), whereas the above mention CGE is in another class (at around $6,000 - it would compete against the Losmandy G11 + Gemini goto class mounts for around $5,500).

Remember for astrophotography you want to really be 20% - 40% under your mounts maximum carrying capacity with all your add ons accounted for.

[Lester]

Hi,

Fork mounts are compact compared to EQ. But for PF photography anywhere near the SCP you will have problems with camera, focal reducer and perhaps off axis guider, because of the room inbetween scope and fork. A good solid EQ mount would be my choice.

[gbeal]

I am died-in-the wool GEM through and through.
I agree with the above comments, and want to add that if the choice is the CG5 or a fork, then the fork may just be better.
IMHO the CG5 is struggling (visually) with an 8" SCT, let alone the 11".
The rule of thumb I use is buy the biggest and best GEM you can, and then look at the scope. I sort of have taken this to the extreme, but I see lots of less than adequate mounts being asked to do more than they are designed for, or capable of.

[Rigel003 (Graeme)]

I have a nexstar 11, the predecessor to the CPC, but essentially the same. Just to give you a different viewpoint, a big attraction is the convenience and simplicity of the setup, especially if you're often having to transport it to dark sites. 2 components only and 5 minutes before you're viewing - no polar aligning necessary. For visual work it's perfect.
In altaz set up it's very stable and suitable for planet webcaming or deepsky photography up to 20 - 30secs if you're willing to stack many short exposures with a DSLR - more than that and field rotation becomes noticable. It can work effectively for deepsky long exposures mounted on a wedge but the G11 would be a better platform if this is your main interest. There is room for a small webcam in any position, and for adaptors and DSLR camera in most except when you're are aimed close to the pole, which isn't such a great loss down here.

[g__day (Matthew)]

I saw the 11" CPC yesterday at astronomy online - its bloody huge and impressive. Anthony said they did some dark sky viewing with it last week and could see a storm forming on Jupiter and a moon cross the face of the planet.

I at first thought it was the 14" beast - it sure looks sexy!